Jet engine with afterburner



July 22, 1952 c. R. BRGWN JET ENGINE WITH AFTERBURNER Filed June 14, 1949 INVENTOR CHARLES R.BROWN ATTOR N EY Patented July 22, 1952 Charles R. Brown, Glen Mills, Pa .assignor, by mesne assignments, to the United States of America as represented by the Secretary ofthe 4 Navy Application June 14, 1949, Serial No. 99,050

7 Claims." (01. 60 35.6)

This invention relates to aircraft power plants, and more particularly tojet apparatus equipped with an afterburner.

With the advent of larger and heavier jet propelled aircraft entailing the use of afterburner apparatus in association with each engine, designers have been confronted with the problem of providing proper support of the elongated en'- velope of each power plant without subjecting it to stresses due to .fiexure of the aircraft{structure during flight operation. To meet this problem it has been proposed'to provide ,independent suport for the engine and the, tailburner together with flexible coupling means permitting relative motion between theseparate casing structures thereof. It is a principal object. of. the present invention to provide an improved jet and tailburner structure of this type having means affording, the desired flexibility while ensuring adequate strength and effective distribution of structural and operationalforces developed under service conditions. a v

A further object of the invention isthe provision of an improvedgasturbine powerplant having a flexible casing structure adapted to meet the exacting weight and dimensional requirements for aircraft service.

These and other objectsare effected by themvention as willrbe-apparent, from therfollowing description and claims taken in connection with the accompanying drawing, forming a part of this application, in which:

Fig. 1 is a diagrammatic elevational view, partly in section, of a gas turbine power plant constructed in accordance with the invention;

Fig. 2 is an enlarged detail sectional view taken along the line II-II of Fig. 1; and

Fig. 3 is a fragmentary enlarged detail view taken along the line III,III of Fig. l.

The typical gas turbine power plant illustrated diagrammatically in Fig. 1 comprises a turbojet engine In and a tailburner'apparatus II, both of which have substantially cylindrical casing structures mounted in coaxial alignment and adapted to be independently supported in the fuselage or wing of an aircraft (not shown). The turbojet engine I0 includes an outer casing I2 and an innercore structure generally indicated at I3, which form an annular passageway I4 extending longitudinally through the engine from a forwardly-directed air intake opening I5 to a rearwardly-disposed turbine discharge passage I6.

annular combustion apparatus I8, and a turbine I9, the rotor of which is operatively connected to the rotor of the compressor through the medium of a common shaft 20 that is suitably journaled within'the core structure I3. In operation, air entering the intake opening I5 is compressed by the compressor I1 and delivered to the combustion apparatus I 8, where fuel supplied by way of nozzles 2| is burned to form hot motive fluid, which. is expanded through the turbine I9 for driving the compressor, and thence supplied through the. discharge passage I6 to the afterburner apparatus II.

The afterburner apparatus I I comprises a-generally cylindrical outer casing 22, the forward end of which is sufficiently large to'overlap or telescope, in a'spaced relation, a portion of the rearmost section. I2a of the turbojet outer casing structure I2, as shown inFig. 1. Mounted in the casing 22' is a tubular combustor or casing section 24, in which is formed an auxiliary combustion chamber 25, which communicates with the turbine discharge passage I6 and terminates in .a discharge opening or nozzle 26, the flow area of which may be controlled by suitable movable tailpiecemembers 21. Auxiliary fuel nozzle apparatus 29 is mounted in the casing section 24 for supplyingfuel to the combustion chamber25. A suitable flame holder or apertured baflie may also be mounted in the chamber 25 downstream of the nozzle apparatus 29. It will be-understood that fuel supplied by way of the nozzle apparatus 29 is burned and the heated gasrand air mixture exhausted from the turbojet unit III to provide additional energy which is expended inpropelling the aircraft upon final discharge of the resultant motive fluid to atmosphere through the variable area nozzle 26.

According to the invention, the engine casing structure I2 and the afterburner casing 22 are flexibly coupled together through the medium of the turbine I 9.by means of a plurality of radially Operating elements of the turbojet engine are mounted in axial alignment to minimize frontal area, andinclude an axial-flow compressor I1,

disposed hollow struts 31, each of which is of airfoil form in cross-section (see Fig. 3) and is welded, or otherwise suitably secured, at its outer end to the casing section I2a. Mounted within the hollow core section 36 is a stationary ball joint member 38 having an enlarged annular mounting portion 39 which is welded to the inner surface of the core section, so that theball '22. "ifldesire'd, be provided adjacent the rear edge of the afterburner casing. 1

joint member is anchored coaxially with respect to the casing structure 12 of the turbojet engine. For supporting the afterburner casing 22 on the ball joint member 38 there is provided a socket joint member 42 engagingthe ball joint member and having a plurality of radially disposed arms v '43, each of which extends through an aperture in the core section into one of the hollow struts 31. The outer ends of the arms 43 project beyond the casing section 12a, and are welded, or otherwise secured, to the portion of the afterburner casing 22 which encompasses the engine casing section l2a. Suitable means such as a ring 44 and bolts may be secured .to the socket joint member 42 for-holding it in rocking engagement with the ball joint member 33.

' It will be noted that the arms 43 are considerably smaller in cross-section than the respective hollow struts 31, so that suflicient space is provided therebetween to permit a limited misalignment or relative flexing movement of the assembled'casing structures of the engine It and'the a-fterburnenfl with respect to the common axis thereof. As best indicated in Fig. 2 of the drawing, limited torsional movement betweenthe casing 22 carried on the "arms 43 and the casing section 12; carried on the struts 31 is likewise facilitated due to the rotatable connection between the ball and socket joint members 38' and 42. With both the engine 19 and th afterburner H suitably mounted in an aircraft fuselage or wine,

the flexible coupling assemblage 35 thus is adapted to permit sufiicient yielding of the power plant casing assembly to prevent undue transmission of strainthereto from the aircraft structure. I

,In orderto minimize leakage of gases in the region of the coupled casing structures [2 and 22, an annular flap seal or flange elementi lfi is preferably mounted on the rearmost marginal portion of the casing section |'2a,;as shown in llig. l'of the drawing; The flange element has an out- 'walrdly flaring flexible skirt portion engageable with the inner surface of the afterburner leasing A similarsealing element (not shown.) may,

"While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof.

1 i What 1 claim is: j

1. In anlaircraft power plant having an outer engine casing and a core structure axially mounted therein, coaxial afterburner apparatus 'there- I for including an outer cylindrical casing structure having a forward end disposedin spaced overlapping relation with respect to the rear end of the first-named casing, and flexible supporting means for said afterburner apparatus including radial struts carried by said engine casing and a-ball joint assembly centrally supported thereon, said ball joint assembly including radial members connected torsaid casing structure of the .afterburner apparatus. 1 r 2 In a power plant for jet propulsion of aircraft comprising main combustion -.apparatus,.a

{substantially cylindrical casing having an axially bination therewith of yield-able coupling means comprising a l stationary ball joint: element mounted on said core structure, a socket joint element movably secured thereto and a plurality of radially-disposed members carried by said afterburner 'easm'g'ror supporting said socket joint element, each of said members extending through one ofsaid hollow struts.

3. Apparatus as set forth in claim 2 wherein an annular flap seal element is interposed between thetelesooped portions of the respective casings of the power plant and afterburner apparatus.

4. Apparatus as set forth in claim 2 wherein the hollow struts and the ball joint supporting members disposed therein are so proportioned as to facilitate limited torsional movementaswell as angular flexure of the assembled 'f'casings centerline of the power plant and afterburner apparatus I ",j

5. In an aircraft 'powerplant having, an outer engine casing and a corev structure axially mounted therein, coaxial afterburner apparatus therefor including an outer cylindrical casing structure having a ,forwardflend disposed spaced'overlapping relation withrespect tothe rear end oi the first named casingand a flexible supporting means for said ,afterburner apparatus including 'radial strutshaving airfoil cross.{sections which struts are jcarriedby saidengine casing and a ball joint assembly centrallyfsupported thereon, said ball jointassembly including means for. securing the afte-rburner apparatus against bodily movement axially of the engine casing I and also including radial members I con nected to the casing structure ,oiflthe afterburner apparatus f f f -6. The combination of claim 5 further defined in that the said radial struts and members are approximately normal toithe axis of the engine. '7. The 'combination'of name further defined in that each of the radial members extend through a radial strut and "that a limited lost motion is provided between theradi'al strutsand the enclosed radial members. ;j 1 1 3 CHARLESR. BROWN;

REFERENCES CITED Y'Ifhe following references are 'ofgecorrl the file of this patent: T

UNITED, STATES 1 PATENTS :7 i 

